Open AccessSpectral-band replication phenomenon in a single pair of hybrid metal-organic nanospheres and nanodisks caused by plexcitonic coupling
Author(s) -
A. D. Kondorskiy,
В. С. Лебедев
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.011783
Subject(s) - plasmon , materials science , hamiltonian (control theory) , molecular physics , degenerate energy levels , j aggregate , chemical physics , coupling (piping) , spectral line , nanoparticle , exciton , condensed matter physics , optics , optoelectronics , physics , nanotechnology , quantum mechanics , mathematical optimization , mathematics , metallurgy
We study an unusual effect of spectral-band replication in the optical spectra of dimers, consisting of spherical nanoparticles or nanodisks with a silver core and a J-aggregate shell of TDBC-dye. It consists in the emergence of a doubled number of plexcitonic spectral bands compared to the case of a plasmonic dimer and in narrow peaks associated with the resonances of the J-aggregate shell. The plexcitonic bands can be divided into two groups: the "original" bands, accurately reproducing plasmonic peaks, and their "replicas," with a specific mutual arrangement and intensity distributions. The effect is interpreted using the multi-state effective Hamiltonian model describing a strong coupling between the quasi-degenerate Frenkel excitonic modes in the organic shells and multiple plasmonic modes in the pair of Ag-cores. We quantitatively explain some available experimental data on the optical properties of nanodisks and suggest a way for the observation of the replication effect. Our results extend the understanding of the nature of plexcitonic coupling to more complex systems compared to individual metal/J-aggregate nanoparticles.